nervous function Flashcards
(12 cards)
function of nervous
The nervous system is responsible for maintaining higher mental functions (such as thinking, memory, and learning), emotional functions, and homeostasis (by regulating internal conditions like temperature, heart rate, and breathing). It also activates muscles and glands, enabling movement and secretion.
HOW: communication of the nervous system either happens chemical or electrical signals
how its done: comunication of nervous system involves electrical signals and chemical signals
2 examples of nervous function
You are driving down the freeway when a horn blares on your right, and you swerve to your left. You are with a group of friends but are not paying attention to any particular conversation, yet when you hear your name, you immediately focus in. What do these events have in common? They are everyday examples of nervous system function, which has your body cells humming with activity all the time.
electrical impulse
The nervous system is the master control and communication system of the body. Every thought, action, and emotion reflects its activity. It communicates with body cells using electrical impulses, which are rapid and specific and cause almost immediate responses.
the nervous system doesnt work alone
The nervous system does not work alone—it works closely with the endocrine system.
While the nervous system uses electrical impulses to send fast, targeted messages, the endocrine system releases hormones into the bloodstream, which act more slowly but have longer-lasting effects.
Because electrical impulses travel rapidly along nerves, the nervous system responds faster than the endocrine system.
stimuli,nput ,interegration,output and effector
Sensory Input
The nervous system uses sensory receptors to detect changes (stimuli) inside and outside the body.
This collected information is called sensory input.
Integration
It processes and interprets the sensory input and decides what action is needed.
This decision-making step is called integration.
Motor Output
Based on the integration, the nervous system sends signals to muscles or glands (called effectors) to cause a response or action.
This is known as motor output.
An example will illustrate how these functions work together. When you are driving and see a red light just ahead (sensory input), your nervous system integrates this information (red light means “stop”) and sends motor output to the muscles of your right leg and foot. Your foot goes for the brake pedal (the response).
the subdivisions of the nervous system.
The structural classification, which includes all nervous system organs, has two subdivisions—the central nervous system and the peripheral nervous system (see Figure 7.2).
central nervous system cns
The CNS consists of the brain and spinal cord.
It is located in the dorsal body cavity (the cranial and vertebral cavities).
The CNS acts as the integrating and command center of the nervous system.
It interprets incoming sensory information and issues instructions based on:
Past experiences
Current conditions
the pereferial nervoes system pns
The PNS includes all parts of the nervous system outside the brain and spinal cord (CNS).
It consists mainly of nerves that extend from the brain and spinal cord:
Spinal nerves: Carry impulses to and from the spinal cord.
Cranial nerves: Carry impulses to and from the brain.
These nerves act as communication lines:
They carry sensory input from receptors to the CNS.
They carry motor output from the CNS to muscles or glands (effectors).
sensory affrent devision pns
The sensory (afferent) division is made up of nerves that carry impulses toward the central nervous system (CNS).
It gathers information from sensory receptors located all over the body and sends it to the CNS.
Its main role is to keep the CNS constantly informed about what’s happening both inside and outside the body.
types of sensory affrent devision
Somatic Sensory (Afferent) Fibers
Carry sensory impulses from the body’s surface and voluntary structures, such as:
Skin
Skeletal muscles
Joints
Arms, legs, fingers, etc.
These help you sense things like touch, pressure, pain, temperature, and body position.
Visceral Sensory (Afferent) Fibers
Carry sensory impulses from internal organs (viscera), such as:
Heart
Lungs
Stomach
Intestines, etc.
These monitor things like hunger, fullness, internal pain, or blood pressure.
🧠 Simple Reminder:
Somatic = Body (outside, voluntary)
Visceral = Organs (inside, involuntary)
motor effrent impulse
The motor (efferent) division carries impulses away from the CNS to effector organs — which are muscles and glands.
Think: “Efferent = Exits the CNS.”
These impulses activate the effectors, causing a motor response — such as:
Muscles contracting (movement)
Glands secreting (like sweat, saliva, hormones)
🧠 Key Point:
subdivisons of motor affrent impulses
Somatic Nervous System (SNS) – Voluntary
Controls skeletal muscles.
Allows for conscious, voluntary movement (e.g., walking, writing).
Referred to as the voluntary nervous system.
⚠️ Exception: Some skeletal muscle actions (like reflexes) are involuntary (e.g., pulling your hand away from a hot surface).
- Autonomic Nervous System (ANS) – Involuntary
Regulates involuntary functions — things you don’t consciously control.
Controls:
Smooth muscle (e.g., intestines, blood vessels)
Cardiac muscle (heart)
Glands (e.g., salivary, sweat, hormone glands)
Referred to as the involuntary nervous system.
Has two subdivisions:
Sympathetic – “fight or flight” (increases heart rate, breathing, etc.)
Parasympathetic – “rest and digest” (slows things down, promotes relaxation and digestion)
